code: def exec(self, *args, **kwargs) -> Iterator[Batch]:
      child_executor = self.children[0]
      for batch in child_executor.exec(**kwargs):
          batch = apply_predicate(batch, self.predicate)
          if not batch.empty():
              yield batch
  
      # perform any required instrumentation before we return
      instrument_function_expression_cost(
          self.predicate, self.catalog()
      )
  
file_path: evadb/evadb/executor/predicate_executor.py
imports: from typing import Iterator
  from evadb.database import EvaDBDatabase
  from evadb.executor.abstract_executor import AbstractExecutor
  from evadb.executor.executor_utils import apply_predicate, instrument_function_expression_cost
  from evadb.models.storage.batch import Batch
  from evadb.plan_nodes.predicate_plan import PredicatePlan
label_desc: Use image node_id 2 for calling the PredicateExecutor obj's underlying member method code with example usage: obj.exec() without return types